quite possible it won't last forever as we see it now. It might transform in some more advanced form, move to the next level. No worries about it.
Every year theres a new technology being discovered, so its really possible for bitcoin to be replace by a new great technology or bitcoin will continue to improve. Well, this will take more time a decade or more because cryptocurrency is still in the early stage so better to enjoy it for now.
Theres is no constant things in this world aside from change, people will come and go, technologies as well. We must be open about it, and dont be afraid to adopt new technologies or invention, the future will make us more better than ever.